Apparatus fob increasing the draft of furnaces



'o NITED sTATEs PATENT oEEioE.

J. B. MARTIN, OF WILMINGTON, NORTH CAROLINA.

APPARATUS FIOR INCREASING THE DRAFT 0F FURNACES Specification of LettersPatent No. 22,814, dated February 1, 1859.

T 0 all whom it may concern.'

Be it known that I, J. B. MARTIN, of Wilmington, county of New Hanover,in the State of North Carolina, have invented certain new and usefulImprovements in Apparatus for Accelerating the Draft of Locomotive andother -Steam Engines and in Arresting the'Discharge of Sparks Therefrom,of which the following isa full, clear, `and accurate description,reference being `had to the accompanying drawings, forming a part ofthis specification, in which- Figure l, represents a section through thesmoke box and stack of a locomotive with my improvements shown inperspective. Fig. 2, represents a transverse horizontal section on theline a: of Fig. l.

Various plans have been proposed for employing the power of t-he exhaustdischarge from locomotives and other engines to accelerate the draft inthe furnace. One of the simplest of these plans is the discharge of theexhaust in the center of the chimney or smoke stack of the engine, thesurrounding air being carried upward by the influence of the blast fromthe exhaust pipe. This plan generally requires a certain amount ofcontraction in the smoke stack to bring the products of combustionissuing from the furnace within the influence of the blast; acontraction which limits to some degree the quantity of air that can bedrawn through the furnace. This plan also requires the elongation of thesmoke stack to produce the most favorable effect, which isdisadvantageous in various ways, preventing the passage of locomotivesunder bridges, arches, or other covered ways, of ordinary elevation, andexposing an undue surface to the resistance of the air, and increasingthe cost of construction. This arrangement has also the furtherdisadvantage that, no obstacle is oered to the discharge of the sparksand cinders, which are compelled to pass with the current of air and canbe only imperfectly intercepted by an additional contrivance in theshape of a spark catcher. Another contrivance consists in passing theexhaust steam over the blades of a revolving fan, which turns upon thesame axis with another fan, in a separate compartment) which is made toforce air into the re box of the locomotive. This is at best but anindirect application of the power of the exhaust, which is muchdiminished by the circuitous path which the air is made to describe. Myplan differs from these, and from all others, in placing the `fandirectly in the path of the exhaust which causes it to turn so that lthe`hack of its blades shall operate to draw the air through the furiiaceand propel it together with the products of `combustion through thestack, thus directly accelerating `the draft through the whole diameterof the stack; however great this may be.

Another branch of my improvement consists `in placing transversedeflecting plates upon the surface of the blades, so that while thegaseous or aeroform products Apass onward the solid matter in the shapeof sparks, cinders or coal, may be detained and allowed to falldownward.

In carrying out my improvenients the smoke stack (A) is best made for acertain length of a cylindrical form. At the upper and lower part ofthis portion cross pieces (a a) are provided, with bearings for thevertical axis (o) of the fan, whose blades (c) are made as is usualinrscrew or other formed fans or propellers, so that. the force of theblast or exhaust pipe (B) upon the blades shall cause the fan to turnand force the air and products of combustion to pass with increasedvelocity through the smoke pipe. At right angles to the axis of the fana set of deflecting plates (d) are arranged so as to aid in detainingthe sparks and cinders as the air passes upward over the face of theblades.

The deflecting plates may be greater or less in size, or they may bemade adjustable to increase or diminish the opening through which theair or steam passes, according to the required force of draft; and theymay, sometimes, be placed on both sides of the blades, so as tointercept the passage of the sparks over both surfaces. therebydiminishing the quantity of cinder or sparks reaching the top of thestack, where any ordinary spark arrester will be sufficient to produce abetter effect, than in a stack blown by the exhaust pipe alone. Thesedeflectors onthe blades are superior to fixed deflectors in the stack,which retard the discharge of the products of combustion, and increasethe quantity of smoke by the imperfect combustion resulting from thediminished supply of air. As solids and gases do not follow strictly thesame law of reflection, after impinging upon a plane, my arrangement ofdeilectors will allow the free discharge of air, and yet, in part, atleast, prevent the cinders from passing upward over the surface of theblades of the fan, even When thc delectors are reduced to mere ridges onthe surface of the blades.

In some cases it may be found desirable to place a series of radialpartitions below the fan, as is done in pumps and Wheels in which suchblades are made to force a fluid or air through a chamber.

I do not intend to limit myself to any particular dimension, number orform, of blade, as long as the fan performs the functions abovedescribed. And in certain cases the deflecting plates, instead of beingat right angles to the axis of the fan, may be made slightly inclinedfrom this position, so as to corroborate the action of the blades, andyet, materially, aid in intercepting the sparks and cinders.

I-Iaving thus described my improvements in apparatus for acceleratingthe draft of locomotives and other steam engines &c.

vv'hat I Claim as my invention and desire to fsecure by Letters PatentisM l. The combination of a fan With the exhaust when arranged Withinthe smoke stack substantially as described, so that the eX- haust steamas it issues from the exhaust pipe acts directly on the blades of thefan, and then passes With the products of combustion in a direct paththrough the fan and through the smoke stack, thus causing the fan toturn With high velocity and thereby accelerating the draft of thefurnace as set forth.

2. The combination of deflecting plates with the blades of the fan, forthe purpose of intercepting sparks and cinders, as above described.

In testimony whereof I have subscribed my name.

J. B. MARTIN. Witnesses:

F. SOUTHGATE SMITH, JOHNS I-IoLLINGsHEAD.

